TISSUE SHEAR MODULUS COMPUTED TOMOGRAPHY BASED ON ULTRASONIC RF-ECHO METHOD

提出了一种利用超声应变测量对浅表组织进行诊断的有效的剪切模量重建技术，即将我们以前开发的超声应变测量方法与剪切模量重建方法相结合并加以加强。该技术实现了很小的计算量，但产生了较高的量化、高稳定性和空间分辨率以及较大的动态范围。在体外猪肋骨和活体人乳腺组织(纤维腺瘤和硬癌)上证明了该方法的可行性。虽然使用典型的工作站(Compaq XP 1000,500 MHz)仅需5分钟即可获得稳定的剪切模量重建图像，但它们在大动态范围内仍具有高稳定性和空间分辨率。因此，这一新发展的成像技术作为一种有效的浅表组织诊断工具具有很大的实用潜力。目前，各种体内剪切模量图正在被获得，以澄清作为一种区分技术进一步应用的任何限制。

An effective shear modulus reconstruction technique was developed which uses ultrasonic strain measurements for diagnosis of superficial tissues, I.e,, our previously developed ultrasonic strain measurement and shear modulus reconstruction methods are combined and enhanced. The technique realizes very low computational load, yet yields fairly high quantitativeness, high stability and spatial resolution, and large dynamic range. The feasibility is demonstrated on in vitro pork ribs and in vivo human breast tissues (fibroadenoma and scirrhous carcinoma). Although the stable shear modulus reconstruction images presented here were obtained in only 5 min using a typical workstation (Compaq XP 1000, 500 MHz), they nevertheless possess high stability and spatial resolution over a large dynamic range. It is therefore expected that this newly developed imaging technique has great potential to be practically used as an effective diagnostic tool for superficial tissues. Presently, a variety of in vivo shear modulus images are being obtained to clarify any limitations for further application as a differentiation technique.